Calcium is a mineral that is important for building bones and teeth. One of the problems with supplementation of the diet with calcium is that all sources of calcium are not equally soluble or bioavailable. In addition, some calcium sources are not as pure as other sources. For example, calcium carbonate derived from bone meal, oyster shell, or other biological origins contains trace amounts of lead and other minerals. Some calcium carbonates also contain silica. Therefore, it is necessary to take additional amounts of these materials to achieve the same calcium level as those taken from synthetic sources which are essentially pure calcium carbonate.
Calcium citrate is poorly soluble in water; 1 gram of calcium citrate dissolves per 1050 grams of cold water. Calcium malate exhibits a similar solubility. Calcium hydroxide is only slightly soluble in water, and it absorbs carbon dioxide from the air readily forming calcium carbonate.
In addition, calcium salts readily hydrate even when stored in dry cool places. Therefore, the amount of calcium being delivered may be even less than expected because of the large amount of water absorbed by the salts.
Therefore a calcium salt which is readily bioavailable and which is readily soluble in neutral solutions as well as acidic solutions is highly desirable. This would allow the calcium salt to be added to neutral as well as acid foods in a soluble form and to be an effective supplement. Granular salts can produce a gritty taste in foods and beverages if they are not soluble or are too large in particle size.
It is therefore an object of this invention to produce a calcium salt which is highly bioavailable and which is readily soluble in water.